Setting up New Inflows While Running Simulations


In this section, a new inflow will be placed near congested areas where it is presumed that re-circulation exists, thus attempting to simulate the 'worst-case' scenario for a gas leak.


Setting up inflows while simulations are running in the simulation scheduler is no different than adding an inflow for the first time. There are no additional steps needed to be performed in order to add inflows while simulations are calculating. in:Flux automates the entire process so no scripting is necessary.


Add a single inflow near the values in the middle of the facility:

  1. Click the Add Item tab and select Gas Leak or Emission from the dropdown menu.

  2. Leave the Name as "HP Release 02"

  3. Set the Gas to METHANE from the dropdown menu.

  4. Leave the Upstream Pressure set to "10" bar(g).

  5. Enter a value of "10" C for the Upstream Temperature of the methane gas.

  6. Leave the Discharge Coefficient as "0.8".

  7. Enter a value of "50" mm Diameter as the hole size.

  8. For the inflow location, click the pick tool button next to the coordinate text boxes:

    1. In the Orientation section change the Pick Tool Rounding to Nearest 15°, as shown in Figure 10. This will increase the accuracy of the direction of the leak which is based on the normal of the point selected by the pick tool.


      Tutorial 5 - Figure 10 - Showing where to change the 'Pick Tool Rounding' amount


    2. Select a point on the tall valve at the northeast corner of the piping of the facility facing towards the flanges, as indicated in Figure 11 and Figure 12 below or manually enter the coordinate "(10.41, 5.37, 5.5)". Since this is a high pressure release, entering the coordinate manually will give a slightly different result than clicking the point in the CAD model. It is recommended if you want results similar to this tutorial to manually enter the values.


      Tutorial 5 - Figure 11 - Indication of HP Release 02 location region


  9. Ensure that the Orientation is set to "45" as the Angle from North and the Elevation to "0" degrees

  10. Click the Preview checkbox to verify the inflow's location and orientation matches that of Figure 12.

  11. Press the Add Item button


    Tutorial 5 - Figure 12 - Location of where to click for new inflow definition as associated direction



Once an inflow has been defined, it can be used as a template for other inflows by selecting the 'Auto-Add' checkbox located next to Discharge Coefficient.


Repeat steps 1 through 11, or use the "Auto-Add' checkbox, to add a "HP Release 03" at the coordinate "(6.19, 15.81, 3.05)" with an Angle from North as "0" degrees and Elevation of "15" degrees. Figure 13 below shows a screenshot of the in:Flux window when adding the third inflow.


Tutorial 5 - Figure 13 - Indication of HP Release 03 location on flanges along the large horizontal tank of the facility


Continue to the next section to determine which ventilation simulations should be run with the HP Release 02 and HP Release 03 leaks for estimating a dispersion of a worst case scenario and determining if it would be picked up by our array of monitor points and monitor lines.